Safety-fuel supply for drying and enameling ovens



Jan. 18, 1927. 1,614,798

A. MAEHLER SAFETY FUEL SUPPLY FOR DRYING' AND ENAMELING OVENS FiledAugust 5; 1926 N' N l? .g El @33- R la A f "D S INVENToR:

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A TTORNE Y.

Patented Jan. 18, 1927.

, `UNITED STATES AB'JPIEITJ'IR' MAEHLER, 0F CHICAGO, ILLINOIS.

SAFETY-FUEL SUPPLY FOR DRYING .AN D ENAMELING OVENS.

Application illed August 5, 1926. Serial No. 127,279.

This invention relates to that type of drying and enameling ovens inwhich heat emplo ed in the operation of the oven is furnislied byburners of the gaseous fuel type, and more especially to that form ofthe same in which the burners are incased to provide indirect heatingunits within the oven chamber with said units having means for aseparate discharge of the products of combustion to the outeratmosphere. And the present im rovement has for its various objects:

il'o provide intercontrolling means between the control valve in thefuel supply pipe to the burner of the heater, and the like control valvein the fuel supply pipe to the pilot light burner, whereby the saidvalves are positively held against either anopening or a closingmovement except -in proper order or sequence, the purpose being toprevent an accidental 'or other escape of unconsumed vgaseous fuel intothe oven chamber and a liability of the explosion of such gaseous fuelin said chamber and the consequent damage to the oven structure andsurrounding objects.

A further object is to provide in connection with the intercontrolledmeans above referred to, of an electric spark ignitionmeans, and whereinthe operating means of a switch controlling the electric circuit of saidignition cans is operatively connected with the operating meansof thepilot light valve, so that the openingl and the closing movements ofsaid pilot light valve will effect a corresponding closing and-openin ofthe circuit of Csaid switch mechanism, a1 as will hereinafter morevfully appear.

In the accompanying drawing:

Fig. 1 is a side elevation showing the preferred form of the safetycontrolling means applied to a drying and enameling oven, the ovenstructure being shown in section. t

Fig. 2, is a detail front elevation, with the parts shown in a positionin which the burner valve is in a closed condition and locked againstrotation and 'in which the pilot light valve is also in a closedcondition ready for an o ening movement. v

Fig. 3, is a etail top view, with the parts in the position set forth inconnection with 2. ike reference numerals indica@ like parts -1n 'theseveral views, f

The oven structure may be of the usual rectangular form, with itsindirect heating units arranged adjacent to the side walls of thechamber of the oven, as described in detail in a companion applicationfor Letters Patent, Serial No. 127,276.

In the construction shown in Fig. 1, the casing 1 of the indirectheating unit is arranged in a lower corner portion of the oven` chamber,and contains the horizontally arranged tubular burner 2 formed with theusual longitudinal series of jet orifices. The forward end of thetubular burner 2 extends out through a front plate 3 fixed on the frontwall of the oven structure for attachment to the usual fuel and airmixing head 4, and the gaseous fuel supply pipe 5 in which is arranged ashut-off valve 6.

In operative relation to the tubular burner ,2 aforesaid, the. pilotlight is arranged with said pilot light comprising a horlzontallyarranged tubular member 7 formed with the usual longitudinal series ofjet openings. The forward end of said tubular member 7 also passes outthrough the front plate 3 aforesaid and has connection with a gaseousfuel supply pipe 8 in which is arranged a shut-off valve 9.

In operative. relation to the aforesaid tubular member 7 vof the pilotlight, an electric ignition means, usually a spark gap plug 10,'passesthrough an orifice in the aforesaid front plate 3, with its electricsupply line provided with av controlling switchxll.

In connection with a burner system such as above described, the presentinvention involves an inter-'controlling connection beween the movablemembers thereof, as folowsz- The shut-olf valves 6 and 9 ,of the fuelsupply pi es 6 and 8, are arranged in adja` cent relation, one to theother, and with the respective movable members 6 and 9 in right-.anglerelation one to the other and with said valve members -carrying fixedcircular disks 12 and 13 in like right-angle relation with theirperimeterof one disk intersecting the perimeter of the other disk with aview t'o an interlocking engagement of said disks as hereinafterdescribed.

Individual notches 14 and 15 are formed in the rimeters of the disks l2and 13,

:with said notches positioned in relation l loo one to the other thatwith the notch of one off valve'9, with said projection so positioneddisk aligned with the perimeter of the companion disk, the perimeter ofsaid companion .disk is free to move in the notch of the first mentioneddisk in a closing or opening of the fuel supply valve with which thelast mentioned disk constitutes a part.

In the described movement or shift of the last mentioned disk itsperimeter has direct engagement in the notch of the first mentiQned diskto prevent any movement of the same and an opening or closing movementof the fuel shut-off valve of which it constitutes a part.

In the practical use of the construction above described and in theinitial portion of its operation, the shut-off valves 6 and 9 in thefuel supply pipes 5 and 8 are in a closed condition with the perimeterof the disk 13 of the pilot light shut-off valve 9 in locking engagementwith the notch 14 of thedisk 12 of the burner shut-off valve 6, to holdthe same in its closed condition.

With a turning movement of the aforesaid disk 13, in attaining andopening of the shutoff valve'9 and a supply of gaseous fuel to t-hepilot light burner 7, the notch 15 in said disk 13 is brought intoalignment with the perimeter of the disk 12, to release the abovementioned locking engagement and admit' of the disk 12 being turned byits operating handle to attain an opening of the shut-0E valve 6 and asupply of gaseous fuel to the tubular burner 2. And in this lastmentioned movement of the disk 12, its perimeter moves into a lockingposition in the notch 15 of the disk 13 of the pilot light shut-olfvalve 9, to prevent a closing of such shut-off valve 9, until the burnervalve 6 and associated parts are returned to the closed condition firstdescribed.

Wit-h the described interconnection of the shut-0H valves and theiroperativo connections, the pilot light must be first started beforegaseous fuel can bo supplied to the heating burner, andthe pilot lightsupply of fuel cannot be shut-off until the fue supply to the heatingburner has been. first shut off. r

Another part of this invention involves an automatic control connectionbetween the operating mechanism of tho pilot light shut-off valve 9 vandthe make and break switch 11 of the electric supply line to the ignitionmeans or spark plug l0, aforesaid, to attain an aetion of said sparkplug 10 simultaneous with the opening of tho pilot light sup ly valve 9,an to such end a connection o parts is provided, as follows A bell-cranklever 16 is pivoted on n convenient stationary part of the structure.with one of its arms in operative contact with the stem of the movablemember of the make and break switch 11 aforesaid, and with its other endarranged in the path of a cam light shutthat in an opening movement ofthe valve 9, the cam projection 17 will operate the bell crank 16 andthe movable member of the switch 11 to close the circuit of said switchand supply electro-motive force to the ignition means or spark plug 10,aforesaid.

Having thus full described my invention, what I claim and dyesire tosecure by Letters Patent, is p l. In a control system for gaseous fuelheating means, the combination of a burner, a pilot light, separatesupply pipes to said burner and pilot light, shut-oli' valves arrangedin sa1d supply pipes, circular disks /having positive operativeconnection with the movable members of said valves, said disks beingarranged in right-angle relation to each other with their erimeters inintersecting relation, each dis having a peripheral notch foralternating locking engagement with the perimeter of the other disk.

. 2. In a control system for gaseous fuel heating means, the combinationof a burner, a pilot light, separate supply pipes to said burner. andpilot li ht, shut-off valves arranged in said supply pipes, circulardisks, having fixed attachment to the movable members ofvsaid valves,said disks being arranged in right angle relation to each other withtheir perimeters y in intersecting relation, each disk having aperipheral notch for alternating locking engagement with the perimeterof the other disk..

3. Ina control system for gaseous fuel heating means, the combination ofa burner, a pilot light, an ignition spark plug, separate supply pipesto said burner and pilot light, shut-oit1 valves in said supply pipes,an electric supply line connected to said spark plug and provided with aswitch, circular disks having positive operative connections with themovable members of said valves, said disks being arranged in right anglerelation to each other with their perimeters in intersecting relation,each vdisk having a peripheral notch for alternate locking engagementwith the perimeter of the other disk with the disk associated with thepilot light shut-ofi' valve carrying a cam projection, and operativeconnections between said cam projection and the movable. connectionsbetween said cam projection and the movable member of the aforesaidswitch in the supply line to the spark plug.

4. In a control system for gaseous fuel heating menus` the combinationof a burner, n. pilot light, an ignition spark plug, separate supplylipes to said burner and light, suit-o valves in said supply pipes, anelectric supply line connecte to .said spark lug and provided with aswitch, circular isks having fixed attachment to the movable members ofsaid valves, said disks being arranged in right-angle relation to so y.

llil) ilot each-other with their eters in intersecttion and the movablemember of the aforeing relation, each di having a peripheral said switchin the supply line to the spark notch for alternate locking e l vgement'yvith plug. l0

the perimeter of the other 'sk, with the Signed at Chicago,v Illinois,July, 1926.

disk associated with the pilot light shut-0E valve carrying a campro]ection, and operat ARTHUR MAEHLER, tive connections between said camprojec-

